1. Field of the Invention
This invention relates to novel compositions which are random interpolymers of a terminally quaternized derivative of acrylic acid with an .alpha.,.beta.-olefinically unsaturated comonomer polymerizable therewith, and to their preparation by polymerization in an aqueous medium. More particularly, this invention relates to hydrophilic interpolymer compositions having novel bacteriostatic properties which, in conjunction with their high water adsorbency, makes them especially suitable for applications where the combination of such water adsorbency with control of bacterial growth is desired.
2. Description of the Prior Art
There has long been a need for polymers which can be prepared by polymerization in aqueous systems and which can be cast as self-supporting films having a large water adsorbent capacity. There has also been a need for such compositions that are bacteriostatic and can therefore control the growth of bacteria on surfaces which they contact. Some polymeric compositions, such as polyvinyl alcohol and cellophane, are excellent film formers yet are unable to adsorb water in appreciable amounts. Other materials, exemplified by the so-called "Hydron" polymers, are more water adsorbent than the above films, but cannot be converted to flexible films from aqueous dispersions. Such materials, if they are to be converted into films, must be polymerized in non-aqueous, organic solvents which are termed "syrups", as disclosed in U.S. Pat. No. 3,520,949. Likewise, these polymers lack bacteriostatic properties. When the above prior art compositions are bacteriostatic, they are rendered so by the inclusion of an additional substance, which is not an integral part of the polymer.